Question

The number of molecules in 73g of HCL

Answer 1

Molecular mass of HCl= 1+35.5=36.5 g
1 g atom of HCl =1 mole = molecular mass =36.5 g
36.5 g contains = Avogadro's no. of molecules = 6.022 *10
73 g will contain = 6.022*10x73/36.5
= 1.2044*10 molecules

Answer 2

Answer: $12.05\times 10^{23}$ molecules

Explanation:

According to Avogadro's law, 1 mole of every substance occupies 22.4 Liters at STP and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:-

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}$

$\text{Number of moles}=\frac{73g}{36.5g/mol}=2moles$

Now 1 mole of $HCl$ molecule contains = $6.023\times 10^{23}$ molecules

2 moles of $HCl$ contains = $\frac{6.023\times 10^{23}}{1}\times 2=12.04\times 10^{23}$ molecules.